Part of the problem I described two posts above was that my mother had birds in cages and stored their food in the same chamber as her own food supplies. She had a large birdcage from floor to ceiling in the lobby. The food chamber was only 10 feet away, easy for the mice to find, and it was just as easy for them to climb the wooden shelves to get everywhere in there .....
The point is, when we recently renovated the flat, my friend opened the old housing for the electrical fuses which was on the wall in that food chamber. He removed half a dozen mummies of mice who had run up the wall to hide when my mother switched on the light in the chamber, crept in it between the fuses and electrocuted themselves when they closed a circuit. And we always wondered about the funny smell in there and why the fuses blew all the time .....